Sole for orthopedic footwear



April 1, 1941. Q U R 2,236,779

SOLE FOR ORTHOPEDIC FOOTWEAR Filed Feb. 23, 1939 I Jaye/22 0 Patented Apr. 1, 1941 Uhll'iE STATES PATENT GFFICE SOLE FOR ORTHO'PEDIC FOOTWEAR Otto Miiller, Frankfort-on-the-Main, Germany Application February 23, 1939, Serial No. 258,003 In Germany August 9, 1937 4 Claim.

purpose, and then molded about the correspond-.

ingly shaped last, whereby it was intended that the sole should assume the shape of the last and should remain in this position. However, due to the tension which is present in the leather and Which is assisted by the exudation ofthefootwhile the footwear is being used, and the permanently acting weight of the body, a sole which has been prepared according to this known method, and constructed as a support for the arch of the foot, soon returns into its initial position and can no longer serve as a support for such arch.

In order to prevent such depression of the upturned sides of the sole, according to the inven tion the tension is withdrawn from the leather at the portions which are arched, by means of lateral incisions whose section surfaces separate the sole entirely or partly. After such incisions have opened upon the arching upwards of the sole side portions involved, for instance, by direct molding about the last, or by pressing in a sole mold, they are connected again, or pasted, by an insoluble adhesive. v

The incisions may be at right angles, or at any other angle, to the surface of the sole and may be made only in one side, namely in the inner side which is turned up highest, or in both sides of the portion of the sole which constitutes the arch. The side incisions can also be so arranged that a correspondingly large wedge-shaped recess is formed which is closed by a pressure member of wedge shape fitting in the recess and consisting of leather or some other pressure-resistant material after the side of the sole has been arched, and secured by a water-insoluble adhesive, so that a permanent arching at this point is obtained.

Preferably, a strip of leather or the like is pasted to the arched portion of the sole at its inner side.

The novel sole, notwithstanding the inherent elasticity of leather, is able to stand comparatively high stress when the footwear is worn for a long period, without being deformed and becoming useless as a support, and without requiring extra supporting means of metal, Celluloid, wood, or the like.

In the drawing various possible constructions of the sole are illustrated in perspective, showing the finished condition of the sole, with lateral incisions only in the inner side at the central portion of the sole.

In the drawing Fig. 1 shows a sole with lateral incisions inclined to its surface.

Fig. 2 shows a sole with vertical lateral incisions extending only for part of the soles thickness.

Fig. 3 shows a sole having inclined incisions and a reinforcing strip on its inner surface.

Fig. 4 shows a sole whose upturned side has a wedge-shaped recess closed by a triangular pressure member.

Fig. 5 is an elevation of a shoe equipped with the sole illustrated in Fig. 4.

Referring now to the drawing, in all figures, the letter a designates a sole, a is its shank por tion which is arched upwardly, and a is its upturned inner side.

Referring now to Fig. 1, b are incisions which are inclined to the surface of the sole and whose section surfaces are connected again after the arching of the sole by a water-insoluble adhesive filling in the gaps formed by the incisions. In this manner, the leather tension is eliminated from the side of the sole at this point so that the side remains in this upwardly arched condition notwithstanding the moist heat and the load acting on the sole when the footwear is being worn.

Referring to Fig. 2, a similar result is produced when the edge of the sole is made with waterinsoluble adhesive filled lateral notches c which do not extend throughout the thickness of the sole so that the lower side of the sole remains closed by the thin layer which has been left.

Referring now to Fig. 3, this sole is made like the one illustrated in Fig. 1 but the water-insoluble adhesive filled incisions are covered by a reinforcing strip 01.

Referring now to Figs. 4 and 5, this sole has a wedge-shaped incision in its inner side and a pressure member e, preferably of the same material as the sole, is inserted in the incision so as to fill it after the sole has been arched, and issecured by a water-insoluble adhesive.

In this manner, undesired tension in the leather is also eliminated and the sole remains in its upwardly arched condition in which it acts as a support for the arched portion of the foot. As shown in Fig. 5, a reinforcing strip d is provided on the incised side of the sole.

I claim:

1. An outsole for orthopedic footwear arranged to support the arch of the foot, having lateral incisions in at least the flesh side thereof and at the side of the shank portion thereof which is arched upwardly, the walls of the incisions being spread apart to form wedge-shaped gaps, and said gaps being filled with a water-insoluble adhesive hardened to render said arched portion relatively stiff and capable of supporting a substantial load without appreciable deformation.

2. An outsole for orthopedic footwear arranged to support the arch of the foot, having lateral incisions at those points of their sides which are arched upwards, the side faces of said incisions which at least partially separate the side portions of the sole, being re-connected by a waterinsoluble adhesive filling the gaps formed by the upward arching of the sides of the sole which open when the sole is, for instance, molded about the shoe last, said sole side incisions being inclined to the surface of the sole, and said adhesive being sufliciently hard to form a structural load-supporting portion of the sole.

3. A sole for orthopedic footwear arranged to support the arch of the foot, as set forth in claim 1, including a reenforcing strip cemented to the sole and covering the adhesive filled incisions.

4. The method of making arch supporting outsoles for footwear which comprises, making a plurality of incisions in the edge of the shank portion of the sole, forming the sole about a last to have an arch-supporting shank portion thereby spreading the walls of the incisions, and filling the spaces formed by the spreading of the incisions with a water-insoluble adhesive which will harden to form wedge shaped elements maintaining the walls of the incisions separated.

OTTO MULLER. 

